Montier



(No Model.)

A. O. DUMONTIER.

KNIFE FOR PLANING MACHINES.

No. 389,139. Y Patented Sept. 4, 1888.

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NITED STATES PATENT OFFICE.

ALEXANDER C. DUMONTIER, OF DETROIT, MICHIGAN, ASSIGNOR OF 'IlVO- THIRDS TO WILLIAM M. D\VIGHT AND FRANK M. LILLIBRIDGE, BOTH OF SAME PLACE.

KNIFE FOR PLANlNG-MACHINES.

SPECIFICATION forming part of Letters Patent No. 389,139, dated September 4, 1888.

(No model.)

To all whom, it may concern:

Be it known that I, ALEXANDER C. DU MONTIER, of Detroit, in the county of \Vayne and State of Michigan, have invented a new and useful ImprovementinKnivesforPlaning- Machines, of which the following is a specification.

My invention relates to knives for planingmachines; and it consists in the novel features [0 of construction hereinafter fully described,aud

then definitely pointed out in the claims.

In the accompanying drawings, Figure 1 is aside elevation; Fig. 2an end elevation; Fig. 3, a plan view of the edge of a planing knife;

Fig. 4, a perspective View showing the planing-knife in position on a cylinder.

A represents a planing-machine knife provided with the ordinary slots, S S, for bolting the same to a cylinder, and B represents the cutting-edge of theknife. As will be seen in Figs. 1 and 3, this cutting-edge, instead of being parallel with the side surfaces of the knifebar, which would make it parallel with the sides of the cylinder when the knife is bolted in place, runs diagonally across the end of the knife-bar, either from corner to corner or at a somewhatgreater or less angle, as preferred, and it is formed by grinding away the sides of the bar in opposite direc o tions, as shown by the lines 0 D. Of course when a knife with such an edge is bolted onto a cylinder with the ends of the knife bar at right angles to the axis of the cylinder it is necessary to make one side of the knife bar 5 longer than the other, as shown in Fig. 1, so that all parts of the cutting-edge B will be at the same distance from the center of rotation of the cylinder; or the same result may be attained by making the knife of equal length at each side and bolting it to the cylinder at such an angle therewith that all parts of the cutting-edge B will be in the same rotary plane.

I prefer to make these knives short, and for wide surfaces to fasten them alternately on 5 opposite sides of the cylinder, so as to cover the whole surface of a board in their rotation, rather than to make a single long knife, as in long knives the inclination of the cutting-edge is less than in a short knife.

\Vhen the knife A is bolted to an ordinary planing-machine cylinder and is set in rotation, the cuttingedge will not all strike the board simultaneously, as is the case with an ordinary knife; but that portion of the edge which is nearest the surface of the knife in 5 contact with the cylinder will strike the board first and will be followed by the rest of the cutting-edge, thus giving the knife a drawing out, which causes it to do much smoother work than the ordinary knife, and also enables the feed to be increased without increasing the speed of the cylindera desirable result in planing-machines.

I am aware that a cylinder has been placed at an angle across the bed of the planer, and 6 that a cylinder set at right angles with the planer has been twisted, the object in both cases being to set an ordinary knife at an angle with the board to be planed for the purpose of obtaining a drawing out; but this method 0 requires either a specially-constructed cylinder, or requires an alteration in the gear of a planing-machine, so that it is not adapted for use on ordinary planer-s as now built, while my invention may be put inany planer whose cylinders are at right angles with the feed without any changes in the gear.

WVhat I claim as my invention, and desire to secure by Letters Patent, is-

1. In combination with the cylinder of a planing-machine placed at right angles across the bed of the machine, a knife having its outting-edge formed diagonally across the end of the knifehar, secured to the cylinder with its cuttingedge all in the same rotary plane,substantially as and for the purpose set forth.

2. A planing-machine knife having its out ting-edge B formed diagonally across the end of the knife with respect to the parallel side surfaces of the knife-bar A, said knife-barbeo ing longer on one side than the other, substantially as described.

ALEX. O. DUMONTIER.

lVitnesses:

HENRY B. LOTHROP, E. HESSELBACHER. 

